1. Field of the Invention
This invention relates to a process for laser drilling blind micro-holes into the surface of a mold or mandrel which can be used to produce shaped articles such as medical devices having a micropillared textured surface thereon. In a more specific embodiment the invention relates to such a process for producing mandrels for formation of micropillared envelopes for mammary prostheses.
2. Prior Art
Laser machining has been employed for various cutting or burning procedures. Computer numerical control (CNC) systems have also been provided to control the motion of such machining systems. See, for example, Polad et al. U.S. Pat. 4,555,610 issued Nov. 26, 1985. Pulsing laser beams controlled by such systems has also heretofore been employed for altering the surfaces of articles, for example, inking rollers.
It has heretofore been proposed that mammary prostheses be constructed which have micropillars on the surface thereof for the purpose of modifying the response of tissue to the prosthesis and possibly reducing the incidence or severity of capsular contracture by the body tissues around such prostheses. Heretofore it has been proposed to form two dimensional, i.e., flat mold surfaces having blind microholes by ion beam thruster bombardment of a surface through sputter-resistant screens or masks in order to cause erosion of the target material at locations corresponding with the openings in the sputter mask or screen. The target material was then, used as a mold surface onto which a silicone or other elastomer was cast to form flat sheets with a micropillared surfaces for lamination onto a three dimensional prosthesis. See Powell E., "Changes in Subcutaneous Tissue Response caused by Implant Compliance and Surface Morphology." Masters Thesis. Case Western Reserve University Cleveland, Ohio, May 1982. Such methods have heretofore enabled construction of a small numbers of implants for experimental purposes but have not resulted in commercial production of prostheses, primarily due to the limitations of the manufacturing process which requires a lamination or bonding step.